Are Humans Done Evolving?

In an interview on the Philosopher's Zone, I heard the following dialog:

Roy Williams: … all species that have ever lived on earth, except for
man, have not been able to discover the laws of physics that underlie
everything.

Alan Saunders: Well they know as much as they need to.

Roy Williams: That's exactly the point… You don't need that ability to
survive as a species on earth, therefore the fact that man alone of all
creatures does understand the underlying laws that go back to the Year Dot,
seems to me a fact of extraordinary significance… because in evolutionary
terms it's quite unnecessary.

Are our brains necessary? Is big brains a complete mess up, or is high
intelligence bound (or even possible) to happen through natural selection?

As my friend, Trent Tobler, once wrote me with an opinion on this subject:

One interesting proposal I have read is that our intellect is the peacock
tail of humanity. The theory goes that male peacocks have this large,
combersome, gaudy tail to advertise to potential mates that not only are they
fit, but are so fit that they can even survive having the handicap of having
this large, gaudy tail that certainly must attract a lot of predators and make
it hard to fly -- and yet, here they are prancing around this very moment. So
it could be with the human mind and 'belief'. The larger, gaudier, useless,
and better, at odds with surviving would advertise a person's prowess at
surviving in spite of the handicaps the beliefs provide must certainly be very
appealing to a member of the opposite gender. It's an interesting theory, in
any case.

I have another proposal… that intellect is an obvious progression. Think of a
predator/prey situation, like Moose and Wolves. Moose are food for wolves,
and by eating them, help to keep the moose population from growing too large
(for if there are too many moose, they will eat everything and starve). But
if the wolves eat too many moose, the resulting food shortage pares down their
number, controlling their population, as well.

In other words, a balance is established. But by natural selection, many
animals often starve. The squirrel caught by a hawk to feed its babies, means
that the squirrel babies die of starvation. The hawk won't intend to, but if
it eats too many parent squirrels, it won't have many squirrels to eat the
following year. So the prey control the predator.

However, there was one predator, that started out being a hunter with many
disadvantages, and compensated by using its ever increasing intellect. This
intellect allowed the species to not be limited by its prey. It hunted the
wild bison in Europe and Asia to extinction, but after putting them in pens,
it could kill the adults this year, but also take care of the babies to kill
the following year.

The species used it intellect to overcome the resource limitation to the
point where the planet has billions of this one particular species, and without
its culture, most of them would die quite quickly.

I previously talked about my ideas of why we evolved brains sufficiently
large to become sentient, whereas the Troodons did not. Without terrible
slashing claws and teeth to hunt, and without feathers to keep us warm, we'd
have to compensate by evolving an ever-increasing brain size.

But I think we are done evolving as a single species.

Why? Well, in order for natural selection to occur, only the "most fit"
should reproduce. In human societies, most have children. And with our
technology, we can take care of humans that never would have survived a
thousand years ago … or even 50.

I'm not suggesting we begin the practice of eugenics, far from it, but
I do think that we will not evolve as a species. Species become two different
species if they live in separate locations long enough, but humans travel and
mate from various backgrounds… shuffling the genes back and forth in different
individual patterns, but not in isolated gene pools. Well, except for maybe
Kentucky.

While I don't think we are evolving biologically , I think we will evolve due
to our technology. Right now, if you are born with a bad hip that would have
made it impossible for you to climb up a tree before the smilodon caught you, we
can, with a simple surgical procedure, fix that. Procedures like this, are
paving the way for more and more integrations of our bodies with our technology.

But don't worry about it. Just like our grandparents didn't complain about eye
glasses, and our parents didn't complain about contacts, and we are not
complaining with laser eye surgery, neither will our children complain about the
telescopic implants to allow us to finally see PowerPoint presentations in the
meetings of the future.

I know what you are thinking… what about the dark side of science? Some
people in the past, have justified their ethnic hatred and intolerance, by
invoking the facts and theories of science. There are also lots of social
issues that we need to grapple and wrestle as technology makes certain things
possible.

For instance, it seems logical that we would want to use the exciting new
field of gene therapy to cure genetic diseases. But of course, this will be
abused with parents picking out their children's eye color. Is that a problem?
The only way we will resolve these issues is by discussing them.

So, how shall we begin?

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Comment

It should probably be noted that evolution, and the idea of 'fitness'
are not specific to the organism. It includes both the critter, and
the environment. In the possible explanation of brain selection based
on sexual selection, the fitness of a smart brain was proposed to be
happening in an environment where lots of potential mates found smart
brains attractive.

Imagine two other possible environments: a 'smart brain neutral'
environment -- potential mates don't care one bit if your are smart or
stupid, and a 'brain antagonistic' environment, where 'smart' is akin
to having a contagious disease and bad breath (I.E, you repel mates
with your smart brain).

Now, certainly, logically, the original environment would have a lot
of positive pressures for getting a bigger brain. You would have all
the positives and negatives for the smart neutral environment, but you
would have all those potential mates fawning over you, and selecting
you over your less brainy compatriots. Statistically, your going to
have more (brainy) children than they are, and your children will tend
to be more like you -- brainy and attracted to brainy.

In the second environment, there may still be some pressure to become
brainy, but other factors in the environment are going to have a
larger play. It also requires a lot more energy, which is not so good
-- Instinct might be a better tactic than general 'smarts' depending
on the environment and environmental change.

In the third environment, you're actually much worse off being smart
(unless you can somehow trick or force those potential mates to bear
your children that give you some kind of advantage over the stupid but
insanely attractive competitors.)

Given the three possible environments, the first two are very likely
to have happened, since, well, here we are, brainy and all. It seems
to me that the first one would more certainly lead to our present
state, and in point of fact, it seems to me that mentally challenged
people have a bit harder time finding a potential mate (when compared
with someone who has the brains, but all else equal.) I think it may
go a little more beyond a simple "I'm smart and can figure out how to
make myself attractive and can survive because I'm so smart" idea -- I
think there still is some sexual bias to braininess.

In any case, on to your technological expansion. Again, selection and
evolution involve both the organism (in this case, humans), and the
environment (in your proposal, an environment where technology is
freely available.) It makes sense to me that higher fitness would be
achieved by individuals that make full use of the technology. However,
they may actually become less fit in other environments (such as one
where technology is NOT freely available). In my mind, there will
always be some pressure to be a generalist (able to get by in many
different environements), rather than a specialist (better than
everyone else in one specific environment, but worse off in all
others), simply because environmental change seems all but
certain. The rate of this environmental change probably has a great
bearing on how effective a more specialized strategy vs. a more
generalized strategy makes sense.

The 'smart' genes may have been selected for via sexual selection, it
may very well hit the lottery on being the ultimate generalist -- able
to survive in many different environments by the ability to think thru
and figure out how to survive in the new environments (either by
adapting behavior to them [I.E, you pace yourself differently when
treking across a swamp vs treking across a desert] -- or by changing
and creating a localized environment more suitable to your survival
[I.E, you build a house.]) The positive feedback forces created a
cascading and self promoting evolution for being much smarter than the
average chimp, even beyond the sexual selection that may have lit the
fuse.